Conventionally, delaminatable containers having an outer shell and an inner bag, the inner bag shrinking upon decrease in the contents, have been known (for example, refer to Patent Literatures 1 to 4).
Regarding the container of the Patent Literature 1, the contents are discharged from the container by compressing the outer shell, and then the initial shape of the outer shell is recovered after discharging the contents.
Regarding the delaminatable container of the Patent Literature 2, a valve member is mounted on the air inlet formed in the outer shell of the container body. This valve member moves relatively with respect to the container body, thereby opening and closing the air inlet.
Further, in the delaminatable container disclosed in Patent Literature 3, a cap valve is built in a cap which is mounted on the mouth of the container body. Regarding the delaminatable container disclosed in Patent Literature 4, the valve is provided at the inner side of the body of the outer shell.
[Patent Literature 1] JP 2015-227206A
[Patent Literature 2] WO/2015/080015
[Patent Literature 3] JP 2013-35557A
[Patent Literature 4] JP H4-267727A